Process of preventing caoutchouc substances from getting sticky and resinous.



UNITED STATES PATENT OFFICE.

FRITZ HOFMANN AND KONRAD DELBRTTCK, OF ELBERFELD, AND KURT MEISENBUBG, 0E LEVERKUSEN, NEAR COLOGNE, GERMANY, ASSIGNORS TO FARBENFAJBRIKEN VORM. FRIEDR. BAYER & 00., 0F ELBERFELD, GERMANY, A CORPORATION OF GER- MANY.

PROCESS OF PREVENTING CAOUTCHOUO SUBSTANCES FROM GETTING STICKY AND RESINOUS.

No Drawing.

in heating butadiene compounds, such as forv instance erythrene, isoprene, beta-gammadimethylerythrene, alpha-methylbutadiene, alpha-dimethylbutadiene, tetramethylbuta (liens, beta-ethylbutadiene, with or without the additionof agents accelerating polymerization, or in submitting these hydrocarbons to the action of alkaline or alkaline earth metals or of mixtures, alloys or amalgams thereof, or in submitting them either at ordinary temperature or heated to the action of organic substances such as starch, albumen, urea, glycerin or compounds of a similar behavior. The caoutchouc substances thus obtained frequently suffer from the disadvantage that they get sticky and turn partially resinous after having been rolled into sheets and dried in the air. lVe have now discovered that this deterioration can be prevented by treating the caoutchouc substances with alkaline agents.

In order to illustrate the new process Specification of Letters Patent.

Application filed December 29, 1911. Serial No. 668,519.

Patented Oct. 1,1912.

more fully the following examples are given, the parts being by weight Example 1: 100 parts of the caoutchouc like product obtained by the/action of heat from beta-gamma-dimethylbutadiene are rolled into thin sheets. The resulting white or more or less colored sheets are then immersed for 24 hours in water containing 2 per cent. of ammonia and dried in the usual way in the open air or in vacuo.

Example 2: 500 parts of the caoutchouc substance obtained by heating beta-gammadiniethylbutadiene are rolled into thin sheets which are then treated for l to 2 days with a solution of dimethylamin. The sheets as sumc on drying a yellowish tint and keep in excellent condition for a long time.

Instead cf the alkaline agents mentioned in. the examples others can be used, as Well as other caontchouc substances obtained by polymerization. of butadiene compounds or mixtures thereof.

We claim Process for preventing the deterioration of synthetic caoutchouc substances, obtainable from butadiene compounds, which process consists in treating these substances with alkaline compounds, substantially as described. i

In testimony whereof we have hereunto set our hands in the presence of two subscribing witnesses.

FRITZ HOFMANN [as] KONRAD DELBRUCK. [as] KURT MEISENBURG. [Ls] Witnesses HELEN NU'FER,

A. NUFER. 

